There's other interesting stuff in the UE University Archives, but the sweat thing made me think of this:
http://ultimateearsuniversity.com/post/25851862168/what-if-i-sweat-a-lot-using-in-ear-monitors
http://ultimateearsuniversity.com/post/25851862168/what-if-i-sweat-a-lot-using-in-ear-monitors